Pistons which act on the carrier plate of brake pads are required for the actuation of hydraulically operated brakes. As a rule, such pistons are cast and then machined. In order to lower the cost of manufacture of such pistons, which are required in huge numbers, it has been proposed to fabricate them without machining, for example by extrusion processes or by hydromechanical forming operations. In this context, the European patent application published without examination, No. 304,103 has, for example, become known. Such pistons have comparatively thin wall thicknesses, and when subjected to the considerable hydraulic forces required to brake larger vehicles, the perimeter wall of the piston may very well be radially distorted. This distortion may cause improper sealing of the piston or improper guidance of the piston in its travel within the cylinder.
The invention has as its object to improve the loading capacity of a piston of this type and to enable a reduction in weight.